Method of electric heating.



PATBNTED APR. 19, 1904.-

w. s.- HURRY. METHOD OF ELECTRIC HEATING. v

APPLICATION FILED JUNE 6, 1902.

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PATENTED APR. 19, 1904.

W. S. HURRY. METHOD OF ELEGTRIG HEATING.

APPLICATION FILED JUNE 6, 1902.

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UNITED STATES Patented April 19, 1904.

PATENT OFFICE.

WILLIAM SMITH HORRY, OF NIAGARA FALLS, NEW YORK, ASSIGNOR TO UNION CARBIDE COMPANY, OF NIAGARA FALLS, NEW YORK, A OOR- PORATION OF VIRGINIA.

METHOD OF ELECTRIC HEATING.

SPECIFICATION forming part of Letters Patent No. 757,620, dated April 19, 1904. I

' Application filed June 6, 1902. Serial No. 110,469. (No specimens.)

To all whom it may concern:

Be it known that I, WILLIAM SMITH HORRY,

a subject of the King of Great Britain, and a resident of Niagara Falls, in the county of Niagara and State of New York, have invented a certain new and useful Method of Electric Heating, of which the following isa specification.

This invention relates to the art of effecting I0 reactions in electric furnaces, and particularly to the formation and withdrawal of calcium carbid.

The object of the invention is to provide a method wherein a body of conductive material in a molten state is interposed between electrodes to establish a path for the electric current and wherein a gradation in the density of the electric current flowing through such conductive body is secured.

I A further object of the invention is to provide a method whereby calcium carbid may be produced and continuously or intermittently tapped from the furnace in a molten state.

Calcium carbid attains a fluidity sufficient to permit of tapping from the furnace only at very high temperatures, and constructions whereby such necessary high temperature may be maintained in the vicinity of the tap-hole 0 of the furnace are illustrated in the accompanying drawings, wherein- Figure 1 is a horizontal section of one form of furnace. Fig. 2 is a vertical central section of the same. Figs. 8 and 4 are modified forms shownin vertical central section. Figs.

5 and 6 illustrate further modifications in vertical central section and in horizontal section,-

respectively. Figs. 7 and 8 show in vertical central section and in horizontal section, re-

4 spectively, a form of furnace wherein the gradation in current density is effected by the arrangement of the electrodes.

Referring to the figures, the furnace comprises a structure having side walls 1 and a base 2, of refractory material. The base may be provided, as shown in Figs. 3, 4, 5,with flues or openings 3 for the circulation of air and with asuitable interior facing 8, of refractory composition. The electrodes 4 5 may be inserted in openings in the furnace-base, as shown in Figs. 1, 2, 3, 5, 6, or may depend from above,

as illustrated in the remaining figures, or may extend through the side walls. 7

' As clearly shown in Figs. 3, 4:, 5, and 7, the electric circuit is completed through a conductive body 6, which may be calcium carbid, iron, carbid of iron, .or other suitablematerial in a molten condition or which may be a conducting mixture of lime and carbon or merely broken carbon, and this body is maintained by the passage of the current at a sufficient temperature to effect the required reaction in adjacent "portions of the superposed furnace charge 7. This charge will for the production of calcium carbid comprise any suit able mixture of carbid and lime.

Referring now more particularly to Figs. 1 l I and 2, the side walls 1 of the furnace are indicated as converging to a central contracted portion, adjacent to which is the electrode5 and the tap-hole 9. Other electrodes, 4 4, of

a polarity opposite to that of the electrode 5, are placed at or near the ends of the furnace. The effect of this construction is to reduce. the cross-sectional area of the conductive body 6 from a maximum in the region of the sity and also the energy density to be maintained at a maximum in the central portion of the conductive body 6. Said conductive body is thereby heated atthis central portion to .a relatively high temperature, and the product of reaction, as calcium carbid, may at this point be most readily withdrawn from the furnace. if the central electrode 5 adjacent to the taphole be omitted, the current passing between the electrodes 4. The increased current and energy density in the contracted portion of the conductor efiects such local increase in temperature as to enable the product to be readily tapped from the furnace.

g In Fig. 3 a form of furnace is shown wherein The same result is accomplished electrodes 4 to a minimum at or near the cen- ,tral electrode 5 and to cause the current denthe conductive body 6 converges to a central contracted portion, said convergence taking place in a vertical plane. This form of furnace may be rectangular in plan, or the side walls also may converge toward the central electrode, as in Fig. 1.

Fig. 4 shows a construction differing in that the central electrode is omitted, the current being conducted to and from the furnace by the electrodes 4 5, situated at or near the ends of the furnace. In this case, also, the highest temperature is developed in a region adjacent to the tap-hole 9. The side walls in this construction may be substantially parallel, or they may converge in the manner shown in Fig. 1.

Figs. 5 and 6 show modified constructions wherein the base and side walls incline toward a tap-hole located at or near one end of the furnace, so as to provide for a graduated reduction of the cross-sectional area of the conductor from end to end of the furnace. The process may be carried out in a furnace wherein the side walls only converge toward the tapping end or in a furnace whose side walls are substantially parallel, the reduction in cross-sectional area of the molten conductor being secured by the inclination of the base, or the converging side walls and inclined base may be combined in a single structure.

Figs. 7 and 8 illustrate a form of furnace which is rectangular in plan and in which the conductive body 6 is of substantially equal cross-sectional area throughout. In this construction the current passes between a plurality of electrodes 4, connected in parallel to one terminal of the source of current, and a plurality of electrodes 5, connected in parallel to the other terminal. As a result of this arrangement the maximum current passes between adjacent electrodes near the center of the furnace, the quantity of current passing, and hence the current density and energy density in the conductor, being progressively increased toward the center. It will be clear that in this construction, as in that shown in Figs. 1, 2, 3, and 4, the current density and the energy density attain a maximum at or near the central portion of the conductive body and the furnace product is tapped out, as indicated at 9, at this point or region of maximum temperature. It is obvious that electrodes may be arranged in this manner in a furnace having side walls converging to a central contracted portion or in a furnace of the type illustrated in Fig. 4, wherein the base alone is inclined or such inclination is combined with convergence of the side walls.

While the operation specifically described is the production of calcium carbid, the process is capable of other applications, as the formation and withdrawal of any molten product from an electric furnace.

The clause maintaining in such pool a region of maximum current density as used in the claims is intended to mean that the current density increases from one portion of the pool to another until it reaches a maximum.

The furnace described in connection with this process is claimed in the joint application of Edgar F. Price and myself, Serial N 0. 126,823, filed October 11, 1902.

I claim- 1. The herein-described process which consists in passing superposed electric currents through a pool of conductive material and thereby maintaining in such pool a region of maximum current density, feeding into con tact with such pool a suitable charge, and withdrawing the product from the region of maximum current density, as set forth.

2. The herein-described process which consists in passing superposed electric currents through a pool of conductive material of varying cross-section and thereby maintaining in such pool a region of maximum current density, feeding into contact with such pool a suitable charge, and withdrawing the product from the region of maximum currentdensity, as set forth.

3. The herein described process which c0nsists in passing superposed electric currents through a pool of calcium carbid and thereby maintaining in such pool a region of maximum current density, feeding into contact with such pool a suitable charge, and withdrawing the product from the region of maximum current density, as set forth.

4. The herein-described process which consists in passing superposed electric currents through a pool of calcium carbid of varying cross-section and thereby maintaining in such pool a region of maximum current density, feeding into contact with such pool a suitable charge, and withdrawing the product from the region of maximum current density, as set forth.

5. The herein-described process of making calcium carbid which consists in passing su perposed electric currents through a pool of conductive material and thereby maintaining in such pool a region of maximum current density, feeding into contact with such pool a mixture of a calcium compound and carbon, thereby producing calcium carbid and withdrawing the carbid from the region of maximum current density, as set forth.

6. The herein-described process of making calcium carbid which consists in passing superposed electric currents through a pool of conductive material of varying cross-section and thereby maintaining in such body a region of maximum current density, feeding into contact with such pool a mixture of a calcium compound and carbon, thereby producing calcium carbid, and withdrawing the carbid from the region of maximum current density, as set forth.

7 The herein-described process of making calcium carbid which consists in passing super- IIO posed electric currents through a pool of calcium carbid and thereby maintaining in such pool a region of maximum current density, feeding into contact with such pool a mixture of a calcium compound and carbon, thereby producing calcium carbid, and withdrawing the carbid from the region of maximum current density, as set forth.

8. The herein-described process which consists in passing superposed electric currents through a pool of calcium carbid, of varying cross-section and thereby maintaining in such body a region of maximum current density, feeding into contact with such pool a mixture of a calcium compound and carbon, thereby producing calcium carbid, and Withdrawing the carbid from the region of maximum current density, as set forth.

9. The herein-described process which consists in passing superposed electric currents through a pool of conductive material and thereby maintaining in such pool a region of maximum energy density, feeding into contact with such pool a suitable charge, and withdrawing the product from the region of maximum energy density, as set forth.

10. The herein-described process which consists in passing superposed electric currents through a pool of conductive material of varying cross-section and thereby maintaining in such pool a region of maximum energy density, feeding into contact with such pool a suitable charge, and withdrawing the product from the region of maximum energy density, as set forth.

11. The herein-described process which consists in passing superposedelectric currents through a pool of calcium carbid and thereby maintaining in such pool a region of maximum energy density, feeding into contact with such pool a suitablecharge, and withdrawing the product from the region of maximum energy density, as set forth.

12. The herein-described process which consists in passing superposed electric currents through a pool of calcium carbid of varying cross-section and thereby maintaining in such pool a region of maximum energy density, feeding into contact with such pool a suitable charge, and withdrawing the product from the region of maximum energy density, as set forth.

13. The herein-described process of making calcium carbid which consists in passing superposed electric currents through a pool of conductive material and thereby maintaining in such pool a region of maximum energy density, feeding into contact with such pool a mixture of a calcium compound and carbon, thereby producing calcium carbid, and withdrawing the carbid from the region of maximum energy density, as set forth. 7

14. The herein-described process of making calcium carbid which consists in passing superposed electric currents through a pool of conductive material of varying cross-section and thereby maintaining in such body a region of maximum energy density, feeding into contact with such pool a mixture of a calcium compound and carbon, thereby producing calcium carbid, and withdrawing the carbid from theregion of maximum energy density, as set forth.

15. The herein-described process of making calcium carbid which consists in passing superposed electric currents through a pool of calcium carbid and thereby maintaining in such pool a region of maximum energy density, feeding into contact with such pool a'mixture of a calcium compound and carbon, thereby producing calcium carbid, and withdrawing the carbid from the region of maximum energy density, as set forth.

16. The herein-described process which consists in passing superposed electric currents through a pool of calcium carbid, of varying cross-section and thereby maintaining in such body a region of maximum energy density, feeding into contact with such pool a mixture of a calcium compound and carbon, thereby producing calcium carbid, and Withdrawing the carbid from the region of maximum energy density, as set forth.

17. The herein-described process which consists in placing three or more electrodes in contact with a pool of conductive material, passing superposed currents'through said pool and thereby maintaining in the pool a region of maximum current density, feeding into contact with said pool a suitable charge, and withdrawing the product from the region of maximum current density, as set forth.

18. The herein-described process which consists in placing three or more electrodes in contact with a pool of calcium carbid, passing superposed electric currents through said pool and thereby maintaining in the pool a region of maximum current density, feeding into contact with said pool a mixture of a calcium compound and carbon, thereby producing calcium carbid, and withdrawing the carbid from the WILLIAM SMITH HORRY.

In presence of- F. E. LAWTON, F. B. OCoNNoR. 

